The U.S. Centers for Disease Control and Prevention (CDC) is calling on public health agencies, emergency departments, and healthcare providers to be alert for patients who develop acute hepatitis or liver failure following the use of a muscle-building nutritional supplement known as OxyElite Pro.

On September 9, the Hawaii Department of Health (DOH) was notified of seven patients suffering from severe acute hepatitis and sudden liver failure due to unknown causes. The seven patients, who had previously been healthy, sought medical care from May through September 2013; all reported usingÂ OxyElite Pro, a dietary supplement marketed for weight loss and muscle gain, according to InfectionControlToday.com.

Kona, Hawaii, resident Thad Estrada, told Hawaii News Now he was admitted to Kaiser Moanalua Medical Center with liver inflammation just days after he stopped using OxyElite Pro, which he first took during part of 2011.

“I noticed that my level of energy didn’t change when I was taking it, so I just stopped taking it altogether because I didn’t think it was working,” he said.

Shortly thereafter, Estrada began to feel fatigued and nauseated. His fiancee noticed his eyes were turning yellow. He was discharged but later got sick again and went to the hospital. Doctors were unable to find a link to his liver failure other than his ingestion of OxyElite Pro, according to Hawaii News Now.

So far, 45 patients have been reported to the Hawaii DOH in response to a public health alert, including the original seven patients. Twenty-nine of those individuals were confirmed to have acute hepatitis after using a nutritional supplement for weight loss and muscle building. Patients reported symptoms such as loss of appetite, light-colored stools, dark urine, and jaundice, InfectionControlToday.com reported.

National case finding efforts have identified several individuals from other states who reported usingÂ OxyElite Pro prior to developing acute hepatitis of unknown cause. The CDC is working with state health departments to gather additional clinical and epidemiologic information from these individuals to help determine if this outbreak is national in scope, InfectionControlToday.com reported.